import java.util.*;
class Example2_5 {
	public static void main (String args[]){
	int start  = 0,end,middle;
	int a[]={12,45,67,89,123,-45,67,20165204};
	int N=a.length;
	for(int i=0;i<N;i++){
	for(int j=i+1;j<N;j++){
		if(a[j]<a[i]);{
			int t=a[j];
			a[j]=a[i];
			a[i]=t;
			}
		}
	}
	Scanner scanner = new Scanner(System.in);
	System.out.println("输入整数，程序判断该整数是否在数组中：");
	int number=scanner.nextInt();
	int count=0;
	end=N;
	middle=(start+end)/2;
	while (number>a[middle]){
		if (number>a[middle])
			start = middle;
		else if(number<a[middle])
			end=middle;
		middle = (start+end)/2;
		count++;
		if(count>N/2)
			break;
	}
		if(count>N/2)
			System.out.printf("%d不在数组中,\n",number);
		else
			System.out.printf("%d在数组中.\n",number);
	}
}
